606 



i^CIENGE. 



[N. S. Vol. IX. No. 226. 



istr3', has showa real progress, especially 

 since 1887, when LeBel and van't Hofif's 

 theory of the asymmetric carbon atom, 

 which was proposed in 1874, but which 

 slumbered almost forgotten, was revived by 

 Wislicenus. At present the most impor- 

 tant developments of structural chemistry, 

 both organic and inorganic, unquestionably 

 have the question of space relation as their 

 basis. 



The development of inorganic chemistry 

 presents some marked distinctions from 

 that of organic chemistry. Up to the year 

 1820 nearly all the important discoveries 

 and genei-alizations came from the inorganic 

 side. Richter's discovery of the law of 

 equivalents; the researches of Scheele, Cav- 

 endish, Priestley; the development of the 

 theory of oxidation by Lavoisier; the atomic 

 hypothesis of Dalton and his laws of con- 

 stant and multiple proportions, and the 

 placing of them on a firm foundation by 

 the remarkable labors of Berzelius ; Gay 

 Lussac's law of the simple relation of 

 the volumes of reacting gases ; Dulong 

 and Petit's law, and the law of iso- 

 morphism, all fall within this period and 

 antedate the beginning of the rapid devel- 

 opment of carbon chemistry. The same is 

 true of the discovery of the alkali metals, 

 the recognition of the elementary nature of 

 chlorine, and of the establishment of the 

 existence of hydrogen acids, and many other 

 important facts. In these the study of car- 

 bon played a relatively insignificant part. 

 The electro-chemical theory of Berzelius, 

 too, which was of such great importance as 

 a working hypothesis, was of inorganic 

 origin. By 1830 the predominance of or- 

 ganic chemistry was already pronounced, 

 and with the increased attention given to 

 this new field the interest in inorganic 

 chemistry lagged behind. All, or nearly 

 all, the developments of theoretical impor- 

 tance began to come from the inorganic side. 

 The history of chemistry from 1830 to 1865 



is practically the history of organic chemis- 

 try. I do not mean that research was con- 

 fined merely to carbon compounds. The 

 influence of Berzelius continued to be felt, 

 and men like Heinrich Rose, Wohler, Bun- 

 sen and many others made valuable contri- 

 butions to inorganic chemistry, as well aa 

 several like Dumas, Liebig and others, 

 whose reputation rests chiefly on their or- 

 ganic work. The great inorganic chemists 

 were mostly men of an analytical rather than 

 synthetical turn of mind. The growth of 

 mineralogy led to the discovery of new ele- 

 ments, and the analytical requirements to 

 which it, as well as practical chemistry, 

 gave rise conduced largely to the study of 

 inorganic compounds. The conception of 

 valency, while due mainly to organic chem- 

 istry, owes not a little to inorganic chemis- 

 try, though it did but little to further it. 

 Numerous atomic weight determinations of 

 greater or less accuracy were made, some- 

 times with a purely analytic purpose, some- 

 times with the object of testing the validity 

 of Prout's hypothesis, but these exercised 

 but little influence on the theoretical growth 

 of inorganic chemistry, which remained for 

 the most part a mass of unconnected facts. 

 In considering the causes to which is due 

 the preeminent attention given to organic 

 chemistry since 1830, the point most to be 

 emphasized is that at no time since that 

 date has there been lacking a well-defined 

 working hypothesis of the nature of organic 

 compounds. Not only did these substances 

 prove eminently susceptible of classification 

 into types, but, for reasons to l^e stated 

 later, the transformations discovered were 

 so numerous, and the possibilities of pro- 

 ducing synthetically old or new compounds, 

 and of working out new theories, were so 

 attractive that most of the best chemical 

 minds between 1830 and 1865, or even later, 

 were drawn into organic chemistry. An- 

 other important factor is that of inertia. 

 Most students of nature do not willingly 



